Turbochargers are forced induction devices that are used to increase intake air pressure to an internal combustion engine. By increasing the air intake pressure, an increase in the power output of the internal combustion engine can be achieved.
In operation, exhaust gases from the engine are routed to the turbocharger to rotate an associated turbine wheel that drives a compressor. The compressor pressurizes ambient intake air to the engine such that the amount of air and fuel that can be forced into each cylinder of the internal combustion engine during an intake stroke of the engine can be increased. Engine exhaust gas employed to operate the turbocharger results in elevated temperature in the turbocharger components. Elevated turbocharger operating temperature can compromise turbocharger performance and durability due to various phenomena such as coking and seal failure. The exhaust gases driving the turbine can cause localized elevated temperatures at the rotor, sometimes reaching levels between 900° and 1000° C. These elevated temperatures can contribute to coking and associated bearing wear of the turbocharger. In some extreme situations, the temperature of the rotor can exceed the temperature at which elastomeric materials in associated seals degrade. It would be desirable to provide a turbocharger capable of effective and balanced heat transfer.